1. Field of the Invention
The invention relates to an illuminating module for a display apparatus, more particularly to an illuminating module in which light rays from a light source can be outputted with a relatively small area of coverage and with a relatively high intensity.
2. Description of the Related Art
Conventional display apparatuses are used to process light from a light source, and include a number of components for performing light filtration, integration, splitting, modulation, synthesis, etc., for subsequent projection on a display panel so as to form images on the display panel for viewing purposes.
FIG. 1 shows a conventional illuminating module 1 for use in a display apparatus. The illuminating module 1 is shown to include an ellipsoidal reflector 11 with an optical axis and first and second focal points, a light source 12 disposed in the reflector 11 at the first focal point, a light integrator 13 disposed on the optical axis at the second focal point to receive light rays that radiate initially toward a reflector surface of the reflector 11 and that are reflected thereby to converge at the second focal point, a first condenser 14 disposed on the optical axis to receive light rays passing through the light integrator 13, a polarization state converter 15 disposed on the optical axis to convert the polarization state of the light rays that pass through the first condenser 14, and a second condenser 16 disposed on the optical axis to condense the light rays passing through the polarization state converter 15 for projection onto a liquid crystal display panel 17. The light integrator 13 may be a rod integrator that can convert the light rays into evenly distributed light rays. The polarization state converter 15 converts the polarization state of light rays that pass therethrough from P-polarization to S-polarization or from S-polarization to P-polarization in a known manner.
In the conventional illuminating module 1, the light rays from the light source 12 are projected on the display panel 17. Since the light rays from the light source 12 have a certain angle of radiation and cover a certain area in a specific direction, and since the light rays projected on the display panel 17 encompass a certain range, in order to achieve a required image brightness, the display panel 17 has to have a certain size. Under the current trend for compact and light products, the size of the display panel 17 will need to be reduced.
Therefore, the main object of the present invention is to provide an illuminating module for a display apparatus, which can reduce the area covered by the light rays outputted thereby so as to permit a reduction in the size of the display panel and which can output light with a relatively high intensity.
Accordingly, an illuminating module of the present invention is adapted for use in a display apparatus, and includes a first reflector, a light source, and a second reflector. The first reflector has a reflector axis, a curved first reflector surface that surrounds the reflector axis, a front surrounding edge which defines a reflector opening that opens forwardly, and a first focal point surrounded by the first reflector surface and disposed on the reflector axis. The light source is disposed in the first reflector at the first focal point. The second reflector is mounted on the front surrounding edge to configure the reflector opening with shielded and unshielded portions. The second reflector has a second reflector surface that faces the first reflector surface. A first portion of light rays from the light source radiates toward the first reflector surface and is reflected by the first reflector surface to pass directly through the unshielded portion of the reflector opening and travel along an optical axis. A second portion of the light rays from the light source initially radiates toward the first reflector surface, and is reflected by the first reflector surface toward the shielded portion of the reflector opening so as to be reflected by the second reflector surface back to the light source so that the second portion of the light rays is able to combine with the first portion of the light rays.